BLACK THEN GREY THEN WHITE SMOKE

[BIG C]

All right, I need some help from those of you with more knowledge then me.
When my mid 92 intercooled truck is running and warmed up, and you stoMp the throttle half way or all the way, it puffs a little black smoke, follwed by a puff of grey smoke that fades to white.
Also the truck has started acting as if it is getting less fuel than before.
I know the smoke screw is turned in 2 turns, the fuel pin is turned with the deepest seting to the front of the engine, and the full power screw is turned inabout 1-1.5 turns past stock.
finally i took a bottle of soap/water and could find no leaks around the injectors, lines, IP, lift pump or fuel filter.

ANY ADVICE IS WOULD BE GREATFULL

[mprmn08]

do you have a fuel pressure gauge?

[PToombs]

Sounds like it is sucking air someplace. Time to put a little pressure on the tank and see if you can find the leak. Might be the fuel heater o-ring too. Been a few of those lately.

[BIG C]

NO. I am planning on installing one over the up coming weekend, if I can get out of some honey dos.
What kind of pressure should one of these make?
pressure to the tank? got an easy method?

[PToombs]

A 30 psi guage should be plenty. The stock LP puts out 7 or 8 tops, and usually around 3-5.

Stuff a rag in the filler neck with a blowgun. Don't go hog wild with the air, the tank is only plastic. Pressurize for a minute or 2, then go look for damp spots. If it's the o-ring on the heater, it won't leak, but it will leak air in. Stupid thing.